"75% Fever After Moderna Second Dose... Higher Rate Than Pfizer"

Research Results from the Japanese Ministry of Health, Labour and Welfare Study Team

COVID-19 vaccines from Pfizer and Moderna.
Photo by Yonhap News

[Asia Economy Reporter Na Ye-eun] A study has found that 75% of people who received the second dose of Moderna's COVID-19 vaccine experienced fever symptoms.

According to Japan's NHK broadcast on the 27th of last month, a research team from Japan's Ministry of Health, Labour and Welfare investigated side effects in 5,178 individuals who received the first dose of the Moderna vaccine and 980 individuals who completed the second dose.

The investigation showed that the rate of fever above 37.5 degrees Celsius the day after the first Moderna vaccine dose was 4.7%, while the rate the day after the second dose was 75.7%. In other words, 3 out of 4 people experienced fever symptoms after the second Moderna vaccine dose, and the research team stated that this rate is higher than that of the Pfizer vaccine.

Additionally, the rate of fatigue experienced was 20.9% the day after the first Moderna dose and 84.7% the day after the second dose. The rate of headache was 11.7% the day after the first dose and 63.8% the day after the second dose.

Sumino Ito, a visiting professor at Juntendo University School of Medicine and leader of the research team, said, "Side effects usually disappear after about three days post-vaccination, but some patients experienced body temperatures rising up to 40 degrees Celsius," and emphasized, "It is recommended to take two days off from work or school after the second vaccine dose."

'Moderna arm' symptoms / Photo by USA TODAY

Furthermore, this study also investigated vaccine side effects known as 'Moderna arm' or 'COVID arm.' 'Moderna arm' refers to a phenomenon where the vaccine activates the immune system, causing the injection site to become red and swollen about three days to a week after vaccination.

According to the survey, 2.15% of 2,325 people who received the first Moderna dose showed symptoms of 'Moderna arm' approximately seven days after vaccination.

Earlier, at the end of last month, Japan's Self-Defense Forces Central Hospital also released similar research results. Analyzing 42,017 people who completed vaccination over a week starting July 1, the hospital found that 2,369 people, or 5.6% of the total, exhibited 'Moderna arm' symptoms. Notably, 83% of those were women, showing a much higher symptom occurrence rate than men.

The U.S. Centers for Disease Control and Prevention (CDC) recommends applying a cold compress to the reddened area to cool the skin and moving the arm to promote blood flow if 'Moderna arm' symptoms appear. Additionally, if the area is itchy, antihistamines are advised, and for pain, acetaminophen such as Tylenol or nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended.

This content was produced with the assistance of AI translation services.